2: Memory and Forgetting
4: Relaxation and Hypnosis
Human memory, like memory in a computer,
allows us to store information for later use. In order to do this, however,
both the computer and we need to master three processes involved in memory.
The first is called encoding;
the process we use to transform information so that it can be stores. For a
computer this means transferring data into 1’s and 0’s. For us, it means
transforming the data into a meaningful form such as an association with an
existing memory, an image, or a sound.
Next is the actual storage,
which simply means holding onto the information. For this to take place, the
computer must physically write the 1’ and 0’s onto the hard drive. It is
very similar for us because it means that a physiological change must occur
for the memory to be stored. The final process is called retrieval,
which is bringing the memory out of storage and reversing the process of
encoding. In other words, return the information to a form similar to what
The major difference between humans and
computers in terms of memory has to do with how the information is stored.
For the most part, computers have only two types; permanent storage and
permanent deletion. Humans, on the other hand are more complex in that we
have three distinct memory storage capabilities (not including permanent
deletion). The first is Sensory
memory, referring to the information we receive through the
senses. This memory is very brief lasting only as much as a few seconds.
Term Memory (STM)
takes over when the
information in our sensory memory is transferred to our consciousness or our
awareness (Engle, Cantor, & Carullo, 1993; Laming, 1992). This is the information that is currently
active such as reading this page, talking to a friend, or writing a paper.
Short term memory can definitely last longer than sensory memory (up to 30
seconds or so), but it still has a very limited capacity. According to
research, we can remember approximately 5 to 9 (7 +/- 2) bits of information
in our short term memory at any given time
If STM lasts only up to 30 seconds, how do we
ever get any work done? Wouldn't we start to lose focus or concentrate
about twice every minute? This argument prompted researchers to look
at a second phase of STM that is now referred to as Working Memory.
Working Memory is the process that takes place when we continually focus on
material for longer than STM alone will allow (Baddeley, 1992).
What happens when our short term memory is
full and another bit of information enters? Displacement
means that the new information will push out part of the old information.
Suddenly some one says the area code for that phone number and almost
instantly you forget the last two digits of the number. We can further
sharpen our short term memory skills, however, by mastering chunking and
using rehearsal (which allows us to visualize, hear, say, or even see the
information repeatedly and through different senses).
Finally, there is long
term memory (LTM), which is most
similar to the permanent storage of a computer. Unlike the other two types,
LTM is relatively permanent and practically unlimited in terms of its
storage capacity. Its been argued
that we have enough space in our LTM to memorize every phone
number in the U.S. and still function normally in terms of remembering what
we do now. Obviously we don’t use even a fraction of this storage space.
There are several subcategories of LTM.
First, memories for facts, life events, and information about our
environment are stored in declarative
memory. This includes semantic
memory, factual knowledge like the meaning of words, concepts, and
our ability to do math (Lesch & Pollatsek, 1993, Rohrer et al., 1995) and
memory, memories for events and situations (Goldringer, 1996;
Kliegel & Lindberger, 1993). The second subcategory is often not thought of as
memory because it refers to internal, rather than external information. When
you brush your teeth, write your name, or scratch your eye, you do this with
ease because you previously stored these movements and can recall them with
ease. This is referred to as nondeclarative
(or implicit) memory. These are memories we have stored due
to extensive practice, conditioning, or habits.
Why We Remember What We Remember
Short Term Memory. There are typically six reasons why information is stored in our
short term memory.
- information that occurs first is typically
remembered better than information occurring later. When given a
list of words or numbers, the first word or number is usually remembered
due to rehearsing this more than other information.
- often the last bit of information is
remembered better because not as much time has past; time which results
- if something stands out from information around it, it is often
remembered better. Any distinctive information is easier to
remember than that which is similar, usual, or mundane.
- rehearsal, as stated in the first example, results in better
memory. Remember trying to memorize a formula for your math class.
The more you went over it, the better you knew it.
- when we associate or attach information to other information it
becomes easier to remember. Many of us use this strategy in our
professions and everyday life in the form of acronyms.
- sometimes we actually fill in the blanks in our memory.
In other words, when trying to get a complete picture in our minds, we
will make up the missing parts, often without any realization that this
Long Term Memory.
Information that passes from our short term to our long term memory is
typically that which has some significance attached to it. Imagine how
difficult it would be to forget the day you graduated, or your first kiss.
Now think about how easy it is to forget information that has no
significance; the color of the car you parked next to at the store or what
shirt you wore last Thursday. When we process information, we attach
significance to it and information deemed important is transferred to our
long term memory.
There are other reasons information is transferred. As we all know,
sometimes our brains seem full of insignificant facts. Repetition
plays a role in this, as we tend to remember things more the more they are
rehearsed. Other times, information is transferred because it is
somehow attached to something significant. You may remember that it
was a warm day when you bought your first car. The temperature really
plays no important role, but is attached to the memory of buying your first
You can’t talk about remembering without
mentioning its counterpart. It seems that as much as we do remember, we
forget even more. Forgetting isn’t really all that bad, and is in
actuality, a pretty natural phenomenon. Imagine if you remembered every
minute detail of every minute or every hour, of every day during your entire
life, no matter how good, bad, or insignificant. Now imagine trying to sift
through it all for the important stuff like where you left your keys.
There are many reasons we forget things and
often these reasons overlap. Like in the example above, some information
never makes it to LTM. Other times, the information gets there, but is lost
before it can attach itself to our LTM. Other reasons include decay, which
means that information that is not used for an extended period of time
decays or fades away over time. It is possible that we are physiologically
preprogrammed to eventually erase data that no longer appears pertinent to
Failing to remember something doesn’t mean
the information is gone forever though. Sometimes the information is there
but for various reasons we can’t access it. This could be caused by
distractions going on around us or possibly due to an error of association
(e.g., believing something about the data which is not correct causing you
to attempt to retrieve information that is not there). There is also the
phenomenon of repression, which means that we purposefully (albeit
subconsciously) push a memory out of reach because we do not want to
remember the associated feelings. This is often sited in cases where adults
‘forget’ incidences of sexual abuse when they were children. And
finally, amnesia, which can be psychological or physiological in origin.